1. field of the Invention
The present invention relates to a process of catalytic steam reforming of hydrocarbons having at least 2 carbon atoms per molecule at a temperature in the range of 300.degree. to 600.degree. C, and to be more precise, it relates to a process of manufacturing a methane-rich gas as the typical product thereof by, for instance, adiabatically steam reforming the hydrocarbon feed material in the presence of a special catalyst capable of demonstrating superior effects particularly in the low-temperature steam reforming of material hydrocarbons containing sulfur compounds.
2. Description of the Prior Art
There have hitherto been proposed a variety of processes of manufacturing a methane-containing gas by subjecting such hydrocarbon feed material as above to low-temperature steam reforming in the presence of a nickel-containing catalyst. To cite instances, there are Japanese Pat. No. 11047/1965 teaching the employment of a catalyst consisting of nickel-alumina-lanthanide, Japanese Pat. No. 11048/1965 teaching the employment of a catalyst consisting of nickel-alumina-iron, Japenese Pat. No. 17737/1969 teaching the employment of a catalyst consisting of nickel-alumina-alkaline earth metal, Japanese pat. No. 19174/1970 teaching the employment of a catalyst consisting of nickel-alumina-aluminium, and so on.
However, these conventional catalysts are more or less apt to give rise to deterioration of the quality when used for a long time -- particularly under the condition of high pressure -- and also deposition of carbonaceous matters, so that the conventional processes employing these catalysts have shown a tendency of having difficulty in maintaining a low-temperature steam reforming operation over a long period of time. Moreover, inasmuch as the conventional nickel-containing catalysts are vulnerable to a sulfur-containing contaminant, in the case of treating such hydrocarbon feed material containing relatively significant amount of sulfur compounds, it has been required to subject said material hydrocarbons to a pretreatment process for desulfurization under severe conditions.